mac80211: Encrypt "Group addressed privacy" action frames

Previously, the action frames to group address was not encrypted. But
[1] "Table 8-38 Category values" indicates "Mesh" and "Multihop" category
action frames should be encrypted (Group addressed privacy == yes). And the
encyption key should be MGTK ([1] 10.13 Group addressed robust management frame
procedures). So this patch modifies the code to make it suitable for spec.

[1] IEEE Std 802.11-2012

Signed-off-by: Masashi Honma <masashi.honma@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

1 files changed, 30 insertions, 0 deletions

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 1daebb307e6e..a80516fd65c8 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -19,6 +19,7 @@
 
 #include <linux/types.h>
 #include <linux/if_ether.h>
+#include <linux/etherdevice.h>
 #include <asm/byteorder.h>
 #include <asm/unaligned.h>
 
@@ -2487,6 +2488,35 @@ static inline bool ieee80211_is_public_action(struct ieee80211_hdr *hdr,
 }
 
 /**
+ * _ieee80211_is_group_privacy_action - check if frame is a group addressed
+ * privacy action frame
+ * @hdr: the frame
+ */
+static inline bool _ieee80211_is_group_privacy_action(struct ieee80211_hdr *hdr)
+{
+	struct ieee80211_mgmt *mgmt = (void *)hdr;
+
+	if (!ieee80211_is_action(hdr->frame_control) ||
+	    !is_multicast_ether_addr(hdr->addr1))
+		return false;
+
+	return mgmt->u.action.category == WLAN_CATEGORY_MESH_ACTION ||
+	       mgmt->u.action.category == WLAN_CATEGORY_MULTIHOP_ACTION;
+}
+
+/**
+ * ieee80211_is_group_privacy_action - check if frame is a group addressed
+ * privacy action frame
+ * @skb: the skb containing the frame, length will be checked
+ */
+static inline bool ieee80211_is_group_privacy_action(struct sk_buff *skb)
+{
+	if (skb->len < IEEE80211_MIN_ACTION_SIZE)
+		return false;
+	return _ieee80211_is_group_privacy_action((void *)skb->data);
+}
+
+/**
  * ieee80211_tu_to_usec - convert time units (TU) to microseconds
  * @tu: the TUs
  */